1. Field of the Invention
The present invention relates to door stops, and more particularly to the exposed area of an elastic bumper in the stops.
2. The Background Art
Door stops are frequently used with doors in a number of configurations. One type of door stop is secured to the floor, and contacts a door when it is opened a desired distance to prevent the door from striking a wall or other obstruction behind the stop. Three commercially available door stops are shown in FIGS. 1-6. One such door stop is illustrated in FIGS. 1 and 2, another door stop is shown in FIGS. 3-5, and a further door stop is shown in FIG. 6 is in accordance with the door stop shown in U.S. Pat. No. 4,209,876.
The prior door stops 10 have a metal retaining member 12 having a shell 14 defining a cavity, and a ledge 16 extending outwardly from a lower portion of the shell 14. The stops 10 have an elastomeric bumper 18 projecting outwardly from the shell 14, with the bumpers 18 defining an elastomeric front surface 20 of the bumper 18 for contacting the door when it is opened. The door stops 10 each have a post 21 depending from the shell 14, and a hole in the ledge 16 to receive a screw or other fastener. When it is desirable to attach the stop 10 to the floor, two spaced holes are drilled into the floor, the post 21 is placed in one of the holes, and a screw is generally applied through the ledge 16 into the floor in order to attach the door stop 10 to the floor.
Within a building, the transition in the type of flooring typically takes place at the doorway from one room to another. The transition from flooring types generally results in a variation in the elevation of the floor within the doorway. In order to accommodate this change in flooring elevation, the door must be cut at the bottom to allow it to swing freely over the flooring. The door stop 10 of FIGS. 1 and 2 is designed to be used in conjunction with flooring which is of a different elevation on either side of the doorway. The taller ledge 16 of this top configuration is designed to make contact with a door with a bottom edge which has been cut to allow the door to swing freely over the higher elevation flooring, such as the instance where the door swings over a tile floor but meets carpeting in the doorway. The door stop 10 of FIGS. 3 and 4 is designed for use on a non-carpeted floor on both sides of the doorway, which does not necessitate removing material from the bottom of the door. Under this circumstance, ledge 16 must be at a low elevation so that the door swings over ledge 16 making contact with elastomeric front surface 20 at a lower elevation.
Unfortunately, the building plans generated by architects do not always indicate what type of flooring is to be applied in each room. As a consequence, the subject door stops supplied to the builder are very frequently not of the appropriate configuration. In those instances where a door stop of the FIG. 1 configuration is required and the builder has been supplied with a FIG. 3 door stop, a lower spacer 22, is traditionally supplied as shown in FIG. 5. This lower spacer 22, when applied under the door stop illustrated in FIG. 3, increases the elevation of ledge 16 to that of the door stop illustrated in FIG. 1.
The economics of exchanging the FIG. 1 stop are highly undesirable as are the economics of the converse. The economics of supplying lower spacer 22 are poor as well. Unfortunately neither of the stops described will allow a single stop to be utilized for all of the floor configurations previously described, without the use of lower spacer 22 which is typically supplied once floor conditions are known. This highly costly and inefficient situation has persisted without improvement for decades.
As a result of the construction of the stops 10 for different types of floors, it has been found that the exposed bumper surface area of these stops 10 is inadequate to permit use of either stop 10 alone on carpeted and non-carpeted floors. For example, the stop of FIGS. 1 and 2 has an exposed area of the bumper 18 having a length of approximately 0.8 inches, and a thickness of the ledge 16 of approximately 0.4 inches. This stop 10 has a ratio of the length of the exposed front surface of the bumper 18 generally perpendicular to the floor to the thickness of the ledge 16 of approximately 2.0 in which the ratio is a measure of the efficiency of the stop 10 since for an increasing ratio, the length of the exposed bumper surface is maximized, and/or the thickness of the ledge 16 is minimized. The stop 10 of FIGS. 3-5 has a length of an exposed surface of the bumper 18 of approximately 0.9 inches, and a thickness of the ledge 16 of approximately 0.2 inches. For this stop 10, the ratio of the length of the exposed bumper surface area to the thickness of the ledge 16 is approximately 4.5. For the commercial stop 10 of FIG. 6, the length of the exposed front surface of the bumper 18 is approximately 0.5 inches, the thickness of the ledge 16 is approximately 0.2 inches, and the ratio of the length of the exposed bumper surface to the thickness of the ledge 16 is approximately 2.5.
It would be immensely desirable to have a door stop similar to those previously described where one door stop configuration would accommodate the entire variety of flooring conditions outlined earlier. By enlarging the exposed height of the bumper 18 and the corresponding ratio of the length of the exposed bumper surface to the thickness of the ledge 16 to provide a door stop that meets this requirement and eliminates the need for a lower spacer 22.